Reconfigurable Fault-Tolerant Tilt-Rotor Quadcopter System

2018 ◽  
Author(s):  
Rumit Kumar ◽  
Siddharth Sridhar ◽  
Franck Cazaurang ◽  
Kelly Cohen ◽  
Manish Kumar
Keyword(s):  
Fault Tolerance ◽  
Dynamic Models ◽  
Fault Tolerant ◽  
Tilt Rotor ◽  
Failure Simulation ◽  
Dynamics And Control ◽  
Space Formulation ◽  
And Control ◽  
Controllability And Observability ◽  
Trim Flight

In this paper, fault-tolerance characteristics of a reconfigurable tilt-rotor quadcopter upon a propeller failure are presented. Traditional quadcopters experience instability and asymmetry about yaw-axis upon a propeller failure but the design and control strategy presented here can handle a complete propeller failure during flight. Fault-tolerance is achieved by means of structural and flight controller reconfiguration. The concept involves conversion of a tilt-rotor UAV into a T-copter. The dynamics and control of the tilt-rotor quadcopter are presented for ideal flight condition and for the reconfigured system in case of propeller failure. Analytical solution for trim flight conditions yielding zero angular rates for the UAV is derived. It has been shown that the structurally reconfigured UAV is controllable and completes the flight mission without much compromise in flight performance. The controllability and observability analysis of the reconfigured system is shown by state space formulation. The flight controllers for both dynamic models are analyzed and the applicability of the proposed concept is presented by propeller failure simulation during the way-point navigation.

scholarly journals Research and development of Q-Baller -- a spherical wheeled robot

2017 ◽  
Author(s):  
◽  
Jiamin Wang
Keyword(s):  
Control System ◽  
Dynamic Models ◽  
Circuit Board ◽  
Embedded Control ◽  
Wheeled Robot ◽  
Dynamics And Control ◽  
Continuous Gain Scheduling ◽  
Machine Interface ◽  
And Control ◽  
And Robotics

The Spherical Wheeled Robot (Ball-Bot) is a family of robots that can maintain balance standing on a ball and use it as its wheel to move around. In recent years, there have been several successful Ball-Bot designs. We attempt to develop a new spherical wheeled robot product named "Q-Baller" to study its dynamics and control system. The Q-Baller has been designed to ahieve the economic and effective prototyping. A detailed dynamic model of the mechatronic system has been established and analyzed. Control studies have been conducted based on the dynamic models, and new control methods has been proposed to realize continuous gain scheduling. Exclusive simulations have been performed to test the performance of the controllers and reference planning. The Q-Baller hardware has been prototyped and functional. Robotic circuit board, human machine interface and embedded control system have also been developed to make up the full robotic system. The Q-Baller prototype will be tested after the system is fully adjusted, and further researches in control and robotics will be conducted in the future.

Passive Fault Tolerance for a Magnetic Bearing Under PID Control

2001 ◽  
Author(s):  
Benjamin Choi ◽  
Andrew Provenza
Keyword(s):  
Fault Tolerance ◽  
Fault Tolerant ◽  
Magnetic Bearing ◽  
System Stability ◽  
Integral Term ◽  
Stability And Control ◽  
Stiffness And Damping ◽  
And Control ◽  
Component Failures ◽  
Detection Mechanisms

NASA Glenn Research Center (GRC) has developed a Fault-Tolerant Magnetic Bearing Suspension rig to enhance the safety of the bearing system for multiple component failures. A simple proportional-integral-derivative (PID) controller with no fault detection mechanisms was tested in a passive way where the initial bias current and control gains for all the eight heteropolar poles were not changed for the remaining active poles in the fault situations. The action of the integral term in the controller generated autonomous corrective actions for the pole failures to return the rotor to the set point (middle position) after the failure transient. The system stability and control of the rotor position were maintained over the entire speed range, where the rotor passes through the rigid body critical speeds and other rotor disturbances, provided that there was sufficient position stiffness and damping at low speeds. As far as the summation of force vectors of two attracting forces and rotor weight is zero, the passive fault tolerance was successfully demonstrated by using as few as two active poles out of the eight independent poles from each radial bearing (that is simply, 12 out of 16 poles dead). The rotor was spun without losing stability or desired position up to the rig’s maximum allowable speed of 20,000 rpm.

scholarly journals Transmission dynamics and control of multidrug-resistant Klebsiella pneumoniae in neonates in a developing country

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Thomas Crellen ◽  
Paul Turner ◽  
Sreymom Pol ◽  
Stephen Baker ◽  
To Nguyen Thi Nguyen ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Neonatal Intensive Care ◽  
Dynamic Models ◽  
Generation Cephalosporin ◽  
Multidrug Resistant ◽  
Transmission Risk ◽  
Dynamics And Control ◽  
One Year ◽  
And Control ◽  
The Impact

Multidrug-resistant Klebsiella pneumoniae is an increasing cause of infant mortality in developing countries. We aimed to develop a quantitative understanding of the drivers of this epidemic by estimating the effects of antibiotics on nosocomial transmission risk, comparing competing hypotheses about mechanisms of spread, and quantifying the impact of potential interventions. Using a sequence of dynamic models, we analysed data from a one-year prospective carriage study in a Cambodian neonatal intensive care unit with hyperendemic third-generation cephalosporin-resistant K. pneumoniae. All widely-used antibiotics except imipenem were associated with an increased daily acquisition risk, with an odds ratio for the most common combination (ampicillin + gentamicin) of 1.96 (95% CrI 1.18, 3.36). Models incorporating genomic data found that colonisation pressure was associated with a higher transmission risk, indicated sequence type heterogeneity in transmissibility, and showed that within-ward transmission was insufficient to maintain endemicity. Simulations indicated that increasing the nurse-patient ratio could be an effective intervention.

scholarly journals Fault-tolerant and energy-efficient MCSoC for information processing and control

2019 ◽  
pp. 9-18
Author(s):  
Aleksandr Gruzlikov ◽  
Nikolai Kolesov ◽  
Dmitri Kostygov ◽  
Marina Tolmacheva
Keyword(s):  
Fault Tolerance ◽  
Energy Efficient ◽  
Fault Tolerant ◽  
Optimal Number ◽  
System Level ◽  
Clock Frequency ◽  
Systems On Chip ◽  
Energy Efficient Architecture ◽  
On Chip ◽  
And Control

Introduction: The majority of real complex systems are designed with respect to fault tolerance requirements. However, all theknown approaches are intended only to increase reliability. Purpose: An approach for designing fault-tolerant systems on a chip, aimednot only at increasing the reliability, but also at reducing the energy consumed by the system. Results: A two-stage approach to thedesign of fault-tolerant multicore systems-on-chip (MCSoCs) is proposed. At the first stage, an energy-efficient architecture of thedesigned system is formed. For each core used in the system, the optimal number of additional cores is determined within the frameworkof the imposed restrictions. The optimality criterion is the minimum power consumed by the system. The algorithm proposed for theformation of an energy-efficient architecture is based on the dependence of the power consumed in the system on the values of the supplyvoltage and the clock frequency. At the second stage, a procedure for diagnosing and repairing the system is developed which uses theprinciples of system-level diagnosis, involving mutual checks between the system cores. This procedure allows you to decentralize theprocess of diagnosing and restoring the system after a failure. Additionally, the article examines the organization of the communicationsubsystem based on shared memory. The study is based on a simulation conducted in order to estimate the time for making a decisionabout a failure in systems such as a lattice, torus and hypercube. Practical relevance: The proposed approach allows a system to providethe necessary values for its two most important characteristics: fault tolerance and energy efficiency. At the same time, decentralizationis ensured when making decisions about a failure and restoration. As a result, the system becomes more reliable.

Dynamics and Control Issues for Fault Tolerance

2009 ◽  
pp. 407-433
Author(s):  
Patrick S. Keogh ◽  
Matthew O.T. Cole
Keyword(s):  
Fault Tolerance ◽  
Dynamics And Control ◽  
And Control

PROJECT ON ELECTRONIC STEERING SYSYTEM

2018 ◽  
Vol 4 (5) ◽  
pp. 7
Author(s):  
Shivam Dwivedi ◽  
Prof. Vikas Gupta
Keyword(s):  
Steering System ◽  
Essential Elements ◽  
Variable Pressure ◽  
Passenger Cars ◽  
Control Techniques ◽  
Steering Mechanism ◽  
Dynamics And Control ◽  
Active Research ◽  
Electronic Steering ◽  
And Control

As the four-wheel steering (4WS) system has great potentials, many researchers' attention was attracted to this technique and active research was made. As a result, passenger cars equipped with 4WS systems were put on the market a few years ago. This report tries to identify the essential elements of the 4WS technology in terms of vehicle dynamics and control techniques. Based on the findings of this investigation, the report gives a mechanism of electronically controlling the steering system depending on the variable pressure applied on it. This enhances the controlling and smoothens the operation of steering mechanism.

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